I can not get any row data from database using c# asp.net.I am trying to fetch one row data from my DB but it is not returning any row.I am using 3-tire architecture for this and i am explaining my code below.
index.aspx.cs:
protected void userLogin_Click(object sender, EventArgs e)
{
if (loginemail.Text.Trim().Length > 0 && loginpass.Text.Trim().Length >= 6)
{
objUserBO.email_id = loginemail.Text.Trim();
objUserBO.password = loginpass.Text.Trim();
DataTable dt= objUserBL.getUserDetails(objUserBO);
Response.Write(dt.Rows.Count);
}
}
userBL.cs:
public DataTable getUserDetails(userBO objUserBO)
{
userDL objUserDL = new userDL();
try
{
DataTable dt = objUserDL.getUserDetails(objUserBO);
return dt;
}
catch (Exception e)
{
throw e;
}
}
userDL.cs:
public DataTable getUserDetails(userBO objUserBO)
{
SqlConnection con = new SqlConnection(CmVar.convar);
try
{
con.Open();
DataTable dt = new DataTable();
string sql = "SELECT * from T_User_Master WHERE User_Email_ID= ' " + objUserBO.email_id + "'";
SqlCommand cmd = new SqlCommand(sql, con);
SqlDataAdapter objadp = new SqlDataAdapter(cmd);
objadp.Fill(dt);
con.Close();
return dt;
}
catch(Exception e)
{
throw e;
}
}
When i am checking the output of Response.Write(dt.Rows.Count);,it is showing 0.So please help me to resolve this issue.
It looks like your your query string has a redundant space between ' and " mark. That might be causing all the trouble as your email gets space in front.
It is by all means better to add parameters to your query with use of SqlConnection.Parameters property.
string sql = "SELECT * from T_User_Master WHERE User_Email_ID=#userID";
SqlCommand cmd = new SqlCommand(sql, con);
cmd.Parameters.Add("#userID", SqlDbType.NVarChar);
cmd.Parameters["#userID"].Value = objUserBO.email_id;
Related
I have fetched the data from SQL server to datagridview but I don't know how to change the cell value. I have to change the fetched value 1 and 0 to available and unavailable. here is my code for fetching data ... please help.
private void btnsearch_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("server = 192.168.100.6;Database=sms;UID=sa;Password=1234;");
SqlCommand cmd = new SqlCommand("Select id as 'Book ID',name as 'Name' , status as 'Status' from book where Name = #name", con);
cmd.Parameters.AddWithValue("#name", txtFirstName.Text);
try
{
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
BindingSource bsource = new BindingSource();
bsource.DataSource = dt;
dataGridView1.DataSource = bsource;
}
catch (Exception ec)
{
MessageBox.Show(ec.Message);
}
// chage_value();
dataGridView1.Show();
}
}
Please find below answer
private void btnsearch_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection("server = 192.168.100.6;Database=sms;UID=sa;Password=1234;");
string sSql=#"Select id as 'Book ID',name as 'Name' ,
Case when status=0 then 'unavailable' else 'available '
End as 'Status' from
book where Name ='"+txtFirstName.Text +"'"
SqlCommand cmd = new SqlCommand(sSql, con);
try
{
SqlDataAdapter da = new SqlDataAdapter();
da.SelectCommand = cmd;
DataTable dt = new DataTable();
da.Fill(dt);
dataGridView1.DataSource = dt;
}
catch (Exception ec)
{
MessageBox.Show(ec.Message);
}
// chage_value();
dataGridView1.Show();
}
}
First of all, try to store your queries in variables. This will help you in the long run. Also, it is good practise to check whether you are connected or not before trying to send a query away to the server. It is important to remeber that when you fetch data from your server, it will most likely be seen as a string, so if you want to compare it as a number, you need to convert it first.
What you could do is something similar to what i've written below. You count the amount of answers your query returns, then loop through them and check whether they are 0 or 1. Then just replace the value with Avaliable or Unavaliable.
if (dbCon.IsConnect()){
MySqlCommand idCmd = new MySqlCommand("Select * from " + da.DataGridView1.Text, dbCon.Connection);
using (MySqlDataReader reader = idCmd.ExecuteReader()){
// List<string> stringArray = new List<string>(); // you could use this string array to compare them, if you like this approach more.
while (reader.Read()){
var checkStatus= reader["Status"].ToString();
Console.WriteLine("Status: " + checkStatus.Split(' ').Count()); //checks how many items you've got.
foreach (var item in checkStatus.Split(' ').Select(x => x.Trim()).Where(x => !string.IsNullOrWhiteSpace(x)).ToArray()){
var item2 = 0.0; // your 0 or 1 for avaliable or unavaliable..
try{
item2 = double.Parse(item.ToString());
if(strcmp(item2,'0') == 1){ //assuming you only have 0's and 1's.
item2 = "unavaliable";
}else{
item2 = "avaliable";
}
}
catch (Exception){
//do what you want
}
Console.WriteLine("item: " + item2);
}
}
dbCon.Close();
}
}
return //what you want;
}
I need some help to complete this. I have searched and tried several ways but is not enetring in my head yet. It is not homework! I am a self learner.
I managed to populate a grid selecting the table from a dropdown:
private void radDropDownList1_SelectedIndexChanged(object sender, Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
{
if (radDropDownList1.SelectedIndex > 0)
{
radGridView1.Visible = true;
label8.Text = radDropDownList1.SelectedValue.ToString();
DataTable dt = new DataTable();
var selectedTable = radDropDownList1.SelectedValue; //Pass in the table name
string query = #"SELECT * FROM " + selectedTable;
using (var cn = new SqlConnection(connString))
{
cn.Open();
try
{
SqlCommand cmd = new SqlCommand(query, cn);
using (var da = new SqlDataAdapter(cmd))
{
da.Fill(dt);
}
}
catch (SqlException ex)
{
//MessageBox.Show(ex.StackTrace);
}
}
radGridView1.DataSource = dt;
}
Now I am trying to write the event to update the sql table using the grid as datasource:
private void radGridView1_CellEndEdit(object sender, Telerik.WinControls.UI.GridViewCellEventArgs e)
{
DataTable dt = (DataTable)radGridView1.DataSource;
DataSet ds = new DataSet();
ds.Tables[0] = dt;
try
{
//**I am lost here!**
}
catch
{
}
}
Could you please help? How can I now update the sql table?
I don't really like the way you are managing the updates but... this code here will send an update statement:
using (var cn = new SqlConnection(connString))
{
cn.Open();
try
{
SqlCommand cmd = new SqlCommand("UPDATE YourTable SET Column = #Parm1 WHERE Col = #Parm2", cn);
var parm1 = cmd.CreateParameter("Parm1");
parm1.Value = "SomeValue";
var parm2 = cmd.CreateParameter("Parm2");
parm2.Value = "SomeOtherValue";
cmd.Parameters.Add(parm1);
cmd.Parameters.Add(parm2);
int rowsAffected = cmd.ExecuteNonQuery();
}
catch (SqlException ex)
{
//MessageBox.Show(ex.StackTrace);
}
}
I got a ComboBox with a table as data source, ID as a value member and a name as a display member.
Selecting a name from the ComboBox should populate 6 TextBoxes with data.
Exception:
The data type is not valid for the boolean operation. [ Data type (if known) = int,Data type (if known) = nvarchar ]
Code:
void FillComboBox()
{
//Fill Combo Box
SqlCeDataAdapter da = new SqlCeDataAdapter(" SELECT CustomerID, Name FROM Customers", clsMain.con);
DataSet ds = new DataSet();
da.Fill(ds);
cBox1.DataSource = ds.Tables[0];
cBox1.ValueMember = "CustomerID";
cBox1.DisplayMember = "Name";
}
public frmMain()
{
InitializeComponent();
}
private void frmMain_Load(object sender, EventArgs e)
{
clsMain.con.ConnectionString = #"Data Source=|DataDirectory|\Database\Sales.sdf";
clsMain.con.Open();
FillComboBox();
}
private void btnSave_Click(object sender, EventArgs e)
{
//Save Button
SqlCeCommand cmd = new SqlCeCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = " INSERT INTO Customers (Name, Phone1, Phone2, Address, Notes) VALUES (#Name, #Phone1, #Phone2, #Address, #Notes) ";
cmd.Connection = clsMain.con;
cmd.Parameters.AddWithValue("#Name", txt2.Text.Trim());
if (txt3.Text != "")
{
cmd.Parameters.AddWithValue("#Phone1", Convert.ToInt32(txt3.Text));
}
else
{
cmd.Parameters.AddWithValue("#Phone1", Convert.DBNull);
}
if (txt4.Text != "")
{
cmd.Parameters.AddWithValue("#Phone2", Convert.ToInt32(txt4.Text));
}
else
{
cmd.Parameters.AddWithValue("#Phone2", Convert.DBNull);
}
cmd.Parameters.AddWithValue("#Address", txt5.Text.Trim());
cmd.Parameters.AddWithValue("#Notes", txt6.Text.Trim());
cmd.ExecuteNonQuery();
MessageBox.Show("Data stored.");
}
private void cBox1_SelectedIndexChanged(object sender, EventArgs e)
{
if (cBox1.SelectedIndex >= 0)
{
String Code = "SELECT * FROM Customers WHERE CustomerID=" + cBox1.SelectedValue.ToString();
SqlCeDataAdapter da = new SqlCeDataAdapter(Code, clsMain.con);
DataSet ds = new DataSet();
da.Fill(ds);
txt1.Text = ds.Tables[0].Rows[0]["CustomerID"].ToString();
txt2.Text = ds.Tables[0].Rows[0]["Name"].ToString();
txt3.Text = ds.Tables[0].Rows[0]["Phone1"].ToString();
txt4.Text = ds.Tables[0].Rows[0]["Phone2"].ToString();
txt5.Text = ds.Tables[0].Rows[0]["Address"].ToString();
txt6.Text = ds.Tables[0].Rows[0]["Notes"].ToString();
}
}
Table Details:
To follow up on my comment (with the caveat that I have never worked with SQL CE, but I'm pretty sure (99.9%) that this is correct).
In you SQL query string, you surround the customer id with single quotes ('). You use single quotes in SQL ("nomral" SQL at least) for character (char\varchar etc) and date values. You pass numeric values without single quotes.
You didn't indicate what line was giving you the exception, but based on the table structure and what you are doing (you gave good detail in your question, by the way), it seems that the error message is telling you that you're trying to compare an int to a varchar, and that's not allowed (because they are different data types, as the error indicates).
To resolve this, simply remove the single quotes from the value in your WHERE clause and construct your query as follows:
String Code = "SELECT * FROM Customers WHERE CustomerID=" + cBox1.SelectedValue;
Thank you, Its working for me.
I am having some customers name in comboBox2. Based on the selected name textbox will return CustomerID and Date of Allocation values.
Following are the code for that:
private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
if(comboBox2.SelectedIndex>0)
{
con = new SqlCeConnection(s);
con.Open();
string code = "select CustomerID,Date_of_Allocation from lockerdetails
where CustomerName='" + comboBox2.SelectedValue.ToString() + "'";
SqlCeDataAdapter da = new SqlCeDataAdapter(code, con);
SqlCeCommandBuilder cmd = new SqlCeCommandBuilder(da);
DataSet ds = new DataSet();
da.Fill(ds);
textBox1.Text = ds.Tables[0].Rows[0]["CustomerID"].ToString();
textBox5.Text = ds.Tables[0].Rows[0]["Date_of_Allocation"].ToString();
}
}
catch(SystemException se)
{
MessageBox.Show(se.Message);
}
I'm trying to use SQL Functions with SQLDataAdabter, but when i run my application i get this exception :
Object reference not set to an instance of an object
in that line :
adbtr.SelectCommand.CommandType = CommandType.Text;
And when i remove that line, i get the same exception but in the line after:
adbtr.SelectCommand.CommandText = "SELECT * FROM Select_gallery_names_FN()";
Here's my code :
protected void Page_Load(object sender, EventArgs e)
{
DataSet dst = new DataSet();
using (SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString))
{
SqlDataAdapter adbtr = new SqlDataAdapter();
adbtr.SelectCommand.CommandType = CommandType.Text;
adbtr.SelectCommand.CommandText = "SELECT * FROM Select_gallery_names_FN()";
try
{
int result = adbtr.Fill(dst);
if (result == 0)
{
return;
}
cat_repeater.DataSource = dst;
cat_repeater.DataBind();
}
catch(Exception ex)
{
Response.Write(ex.Message);
}
}
Any help would be appreciated. Thanks.
You need to initialize the SelectCommand.. it is null at the time you're setting properties on it:
SqlDataAdapter adbtr = new SqlDataAdapter();
adbtr.SelectCommand = new SqlCommand("SELECT * FROM Select_gallery_names_FN()");
adbtr.SelectCommand.CommandType = CommandType.Text;
I've tried various solutions I have found and either I don't know how to implement them properly or they simply won't work. I have a method that allows someone to search a table for a specific order number, then the rest of the row will display in a gridview. However, if an order number is entered that doesn't exist in the table then I can get server error/exception. How can I make it so that before the search goes through or while the search goes through, if an order number that does't exist in the database is searched for then I can create the error instead?
I am using an ms access database, C#, and ASP.
Here is some of the code I am working with:
the method for searching the order table:
public static dsOrder SearchOrder(string database, string orderNum)
{
dsOrder DS;
OleDbConnection sqlConn;
OleDbDataAdapter sqlDA;
sqlConn = new OleDbConnection("PROVIDER=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + database);
DS = new dsOrder();
sqlDA = new OleDbDataAdapter("select * from [Order] where order_num='" + orderNum + "'" , sqlConn);
sqlDA.Fill(DS.Order);
return DS;
}
And using that method:
protected void btnSearch_Click(object sender, EventArgs e)
{
Session["OrderNum"] = txtSearch.Text;
Session["ddl"] = ddlSearch.Text;
if (Session["ddl"].ToString() == "Order")
{
dsOrder dataSet2;
dataSet2 = Operations.SearchOrder(Server.MapPath("wsc_database.accdb"), Session["OrderNum"].ToString());
grdSearch.DataSource = dataSet2.Tables["Order"];
grdSearch.DataBind();
}
Do I need to do a try/catch?
A huge thanks in advance to who is able to help me!
You can simply do a check to see whether DataSet is empty
if (dataSet2 == null || dataSet2.Tables.Count == 0 || dataSet2.Tables["Order"] == null || dataSet2.Tables["Order"].Rows.Count == 0)
{
//display error to user
}
else
{
// your code to populate grid
}
If you don't want to show error then just put this check before populating GridView
if (dataSet2.Tables != null && dataSet2.Tables["Order"] != null)
{
// your code to populate grid
}
I use a different approach when filling data grids and always use parameters as follows:
public static DataTable GetGridDatasource(string database, string ordnum) {
using (OleDbConnection con = new OleDbConnection("PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source=" + database))
{
con.Open();
OleDbCommand cmd = con.CreateCommand();
cmd.CommandText = "select * from [Order] where order_num=[OrderNumber]";
cmd.CommandType = CommandType.Text;
cmd.Parameters.AddWithValue("OrderNumber", ordnum);
OleDbDataAdapter da = new OleDbDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
return dt;
}
}
protected void btnSearch_Click(object sender, EventArgs e)
{
Session["OrderNum"] = txtSearch.Text;
Session["ddl"] = ddlSearch.Text;
if (Session["ddl"].ToString() == "Order")
{
grdSearch.DataSource = GetGridDatasource(Server.MapPath("wsc_database.accdb"), Session["OrderNum"].ToString());
}
}